This chapter reviews the subfield of cleavage research - the sub-field within which this special issue fits. It assesses the strengths and weaknesses of the sub-field and characterises it as (with some shining exceptions) being prone to weak theorising, loose logic, and/or shaky methodology (sometimes all three at once). These three themes are pursued in three separate sections of the article, after which the contents of the special issue are themselves assessed in the same terms.